How-to configure the Jump to Extent Drop Down
=============================================

Changing the defined extents
----------------------------

The JumpToExtent component is configured in the ``app.js`` file.

The JumpToExtent component's configuration offers the ``locations``
settings which is an array of objects with a ``label`` and ``extent``
attribute. The ``extent`` is an array of minx,maxx,miny,maxy in the
map's coordinate system. The examples below are in EPSG:3857.

From the example app:

.. code:: javascript

    app.add(gm3.components.JumpToExtent, 'jump-to-extent', {
        locations:  [
            {
                label: 'Parcel Boundaries',
                extent: [-10384071.6,5538681.6,-10356783.6,5563600.1]
            },
            {
                label: 'Dakota County',
                extent: [-10381354,5545268,-10328765,5608252]
            },
            {
                label: 'Minnesota',
                extent: [-10807000,5440700,-9985100,6345700]
            }
        ]
    });

Getting the configuration from a JSON file
------------------------------------------

The component can be added asynchronously as a part of a AJAX call. For
example, if there was a ``locations.json`` file it could be loaded using
the Fetch API:

.. code:: javascript

    fetch('locations.json').then(function(response) {
        return response.json();
    }).then(function(locationsJson) {
        app.add(gm3.components.JumpToExtent, 'jump-to-extent', {
            locations: locationsJson
        });
    });